# Copyright 2015-2019 Onestein (<https://www.onestein.eu>)
# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).

import base64
import json
import pydot
from psycopg2.extensions import AsIs

from odoo import _, api, fields, models, tools
from odoo.exceptions import UserError, ValidationError


class BveView(models.Model):
    _name = 'bve.view'
    _description = 'BI View Editor'

    @api.depends('group_ids', 'group_ids.users')
    def _compute_users(self):
        for bve_view in self.sudo():
            if bve_view.group_ids:
                bve_view.user_ids = bve_view.group_ids.mapped('users')
            else:
                bve_view.user_ids = self.env['res.users'].sudo().search([])

    @api.depends('name')
    def _compute_model_name(self):
        for bve_view in self:
            name = [x for x in bve_view.name.lower() if x.isalnum()]
            model_name = ''.join(name).replace('_', '.').replace(' ', '.')
            bve_view.model_name = 'x_bve.' + model_name

    def _compute_serialized_data(self):
        for bve_view in self:
            serialized_data = []
            for line in bve_view.line_ids.sorted(key=lambda r: r.sequence):
                serialized_data.append({
                    'sequence': line.sequence,
                    'model_id': line.model_id.id,
                    'id': line.field_id.id,
                    'name': line.name,
                    'model_name': line.model_id.name,
                    'model': line.model_id.model,
                    'type': line.ttype,
                    'table_alias': line.table_alias,
                    'description': line.description,
                    'row': line.row,
                    'column': line.column,
                    'measure': line.measure,
                    'list': line.in_list,
                    'join_node': line.join_node,
                    'relation': line.relation,
                })
            bve_view.data = json.dumps(serialized_data)

    def _inverse_serialized_data(self):
        for bve_view in self:
            line_ids = self._sync_lines_and_data(bve_view.data)
            bve_view.write({'line_ids': line_ids})

    name = fields.Char(required=True, copy=False)
    model_name = fields.Char(compute='_compute_model_name', store=True)
    note = fields.Text(string='Notes')
    state = fields.Selection([
        ('draft', 'Draft'),
        ('created', 'Created')
    ], default='draft', copy=False)
    data = fields.Char(
        compute='_compute_serialized_data',
        inverse='_inverse_serialized_data',
        help="Use the special query builder to define the query "
             "to generate your report dataset. "
             "NOTE: To be edited, the query should be in 'Draft' status.")
    line_ids = fields.One2many(
        'bve.view.line',
        'bve_view_id',
        string='Lines')
    field_ids = fields.One2many(
        'bve.view.line',
        'bve_view_id',
        domain=['|', ('join_node', '=', -1), ('join_node', '=', False)],
        string='Fields')
    relation_ids = fields.One2many(
        'bve.view.line',
        'bve_view_id',
        domain=[('join_node', '!=', -1), ('join_node', '!=', False)],
        string='Relations')
    action_id = fields.Many2one('ir.actions.act_window', string='Action')
    view_id = fields.Many2one('ir.ui.view', string='View')
    group_ids = fields.Many2many(
        'res.groups',
        string='Groups',
        help="User groups allowed to see the generated report; "
             "if NO groups are specified the report will be public "
             "for everyone.")
    user_ids = fields.Many2many(
        'res.users',
        string='Users',
        compute='_compute_users',
        store=True)
    query = fields.Text(compute='_compute_sql_query')
    over_condition = fields.Text(
        states={
            'draft': [
                ('readonly', False),
            ],
        },
        readonly=True,
        help="Condition to be inserted in the OVER part "
             "of the ID's row_number function.\n"
             "For instance, 'ORDER BY t1.id' would create "
             "IDs ordered in the same way as t1's IDs; otherwise "
             "IDs are assigned with no specific order.",
    )
    er_diagram_image = fields.Binary(compute='_compute_er_diagram_image')

    _sql_constraints = [
        ('name_uniq',
         'unique(name)',
         _('Custom BI View names must be unique!')),
    ]

    @api.depends('line_ids')
    def _compute_er_diagram_image(self):
        for bve_view in self:
            graph = pydot.Dot(graph_type='graph')
            table_model_map = {}
            for line in bve_view.field_ids:
                if line.table_alias not in table_model_map:
                    table_alias_node = pydot.Node(
                        line.model_id.name + ' ' + line.table_alias,
                        style="filled",
                        shape='box',
                        fillcolor="#DDDDDD"
                    )
                    table_model_map[line.table_alias] = table_alias_node
                    graph.add_node(table_model_map[line.table_alias])
                field_node = pydot.Node(
                    line.table_alias + '.' + line.field_id.field_description,
                    label=line.description,
                    style="filled",
                    fillcolor="green"
                )
                graph.add_node(field_node)
                graph.add_edge(pydot.Edge(
                    table_model_map[line.table_alias],
                    field_node
                ))
            for line in bve_view.relation_ids:
                field_description = line.field_id.field_description
                table_alias = line.table_alias
                diamond_node = pydot.Node(
                    line.ttype + ' ' + table_alias + '.' + field_description,
                    label=table_alias + '.' + field_description,
                    style="filled",
                    shape='diamond',
                    fillcolor="#D2D2FF"
                )
                graph.add_node(diamond_node)
                graph.add_edge(pydot.Edge(
                    table_model_map[table_alias],
                    diamond_node,
                    labelfontcolor="#D2D2FF",
                    color="blue"
                ))
                graph.add_edge(pydot.Edge(
                    diamond_node,
                    table_model_map[line.join_node],
                    labelfontcolor="black",
                    color="blue"
                ))
            try:
                png_base64_image = base64.b64encode(graph.create_png())
                bve_view.er_diagram_image = png_base64_image
            except:
                bve_view.er_diagram_image = False

    def _create_view_arch(self):
        self.ensure_one()

        def _get_field_def(line):
            field_type = line.view_field_type
            return '<field name="%s" type="%s" />' % (line.name, field_type)

        bve_field_lines = self.field_ids.filtered('view_field_type')
        return list(map(_get_field_def, bve_field_lines))

    def _create_tree_view_arch(self):
        self.ensure_one()

        def _get_field_attrs(line):
            attr = line.list_attr
            res = attr and '%s="%s"' % (attr, line.description) or ''
            return '<field name="%s" %s />' % (line.name, res)

        bve_field_lines = self.field_ids.filtered(lambda l: l.in_list)
        return list(map(_get_field_attrs, bve_field_lines))

    def _create_bve_view(self):
        self.ensure_one()
        View = self.env['ir.ui.view'].sudo()

        # delete old views
        View.search([('model', '=', self.model_name)]).unlink()

        # create views
        View.create([{
            'name': 'Pivot Analysis',
            'type': 'pivot',
            'model': self.model_name,
            'priority': 16,
            'arch': """<?xml version="1.0"?>
                       <pivot string="Pivot Analysis">
                       {}
                       </pivot>
                    """.format("".join(self._create_view_arch()))
        }, {
            'name': 'Graph Analysis',
            'type': 'graph',
            'model': self.model_name,
            'priority': 16,
            'arch': """<?xml version="1.0"?>
                       <graph string="Graph Analysis"
                        type="bar" stacked="True">
                        {}
                       </graph>
                    """.format("".join(self._create_view_arch()))
        }, {
            'name': 'Search BI View',
            'type': 'search',
            'model': self.model_name,
            'priority': 16,
            'arch': """<?xml version="1.0"?>
                       <search string="Search BI View">
                       {}
                       </search>
                    """.format("".join(self._create_view_arch()))
        }])

        # create Tree view
        tree_view = View.create({
            'name': 'Tree Analysis',
            'type': 'tree',
            'model': self.model_name,
            'priority': 16,
            'arch': """<?xml version="1.0"?>
                       <tree string="List Analysis" create="false">
                       {}
                       </tree>
                    """.format("".join(self._create_tree_view_arch()))
            })

        # set the Tree view as the default one
        action = self.env['ir.actions.act_window'].sudo().create({
            'name': self.name,
            'res_model': self.model_name,
            'type': 'ir.actions.act_window',
            'view_type': 'form',
            'view_mode': 'tree,graph,pivot',
            'view_id': tree_view.id,
            'context': "{'service_name': '%s'}" % self.name,
        })

        self.write({
            'action_id': action.id,
            'view_id': tree_view.id,
            'state': 'created'
        })

    def _build_access_rules(self, model):
        self.ensure_one()

        if not self.group_ids:
            self.env['ir.model.access'].sudo().create({
                'name': 'read access to ' + self.model_name,
                'model_id': model.id,
                'perm_read': True,
            })
        else:
            # read access only to model
            access_vals = [{
                'name': 'read access to ' + self.model_name,
                'model_id': model.id,
                'group_id': group.id,
                'perm_read': True
            } for group in self.group_ids]
            self.env['ir.model.access'].sudo().create(access_vals)

    def _create_sql_view(self):
        self.ensure_one()

        view_name = self.model_name.replace('.', '_')
        query = self.query and self.query.replace('\n', ' ')

        # robustness in case something went wrong
        self._cr.execute('DROP TABLE IF EXISTS %s', (AsIs(view_name), ))

        # create postgres view
        try:
            with self.env.cr.savepoint():
                self.env.cr.execute('CREATE or REPLACE VIEW %s as (%s)', (
                    AsIs(view_name), AsIs(query), ))
        except Exception as e:
            raise UserError(
                _("Error creating the view '{query}':\n{error}")
                .format(
                    query=query,
                    error=e))

    @api.depends('line_ids', 'state', 'over_condition')
    def _compute_sql_query(self):
        for bve_view in self:
            tables_map = {}
            select_str = '\n CAST(row_number() OVER ({}) as integer) AS id' \
                .format(bve_view.over_condition or '')
            for line in bve_view.field_ids:
                table = line.table_alias
                select = line.field_id.name
                as_name = line.name
                select_str += ',\n {}.{} AS {}'.format(table, select, as_name)

                if line.table_alias not in tables_map:
                    table = self.env[line.field_id.model_id.model]._table
                    tables_map[line.table_alias] = table
            seen = set()
            from_str = ""
            if not bve_view.relation_ids and bve_view.field_ids:
                first_line = bve_view.field_ids[0]
                table = tables_map[first_line.table_alias]
                from_str = "{} AS {}".format(table, first_line.table_alias)
            for line in bve_view.relation_ids:
                table = tables_map[line.table_alias]
                table_format = "{} AS {}".format(table, line.table_alias)
                if not from_str:
                    from_str += table_format
                    seen.add(line.table_alias)
                if line.table_alias not in seen:
                    seen.add(line.table_alias)
                    from_str += "\n"
                    from_str += " LEFT" if line.left_join else ""
                    from_str += " JOIN {} ON {}.id = {}.{}".format(
                        table_format,
                        line.join_node, line.table_alias, line.field_id.name
                    )
                if line.join_node not in seen:
                    from_str += "\n"
                    seen.add(line.join_node)
                    from_str += " LEFT" if line.left_join else ""
                    from_str += " JOIN {} AS {} ON {}.{} = {}.id".format(
                        tables_map[line.join_node], line.join_node,
                        line.table_alias, line.field_id.name, line.join_node
                    )
            bve_view.query = """SELECT %s\n\nFROM %s
                """ % (AsIs(select_str), AsIs(from_str),)

    def action_translations(self):
        self.ensure_one()
        if self.state != 'created':
            return
        self = self.sudo()
        model = self.env['ir.model'].search([('model', '=', self.model_name)])
        IrTranslation = self.env['ir.translation']
        IrTranslation.translate_fields('ir.model', model.id)
        for field in model.field_id:
            IrTranslation.translate_fields('ir.model.fields', field.id)
        return {
            'name': 'Translations',
            'res_model': 'ir.translation',
            'type': 'ir.actions.act_window',
            'view_mode': 'tree',
            'view_id': self.env.ref('base.view_translation_dialog_tree').id,
            'target': 'current',
            'flags': {'search_view': True, 'action_buttons': True},
            'domain': [
                '|',
                '&',
                ('res_id', 'in', model.field_id.ids),
                ('name', '=', 'ir.model.fields,field_description'),
                '&',
                ('res_id', '=', model.id),
                ('name', '=', 'ir.model,name')
            ],
        }

    def action_create(self):
        self.ensure_one()

        # consistency checks
        self._check_invalid_lines()
        self._check_groups_consistency()

        # force removal of dirty views in case something went wrong
        self.sudo().action_reset()

        # create sql view
        self._create_sql_view()

        # create model and fields
        bve_fields = self.line_ids.filtered(lambda l: not l.join_node)
        model = self.env['ir.model'].sudo().with_context(bve=True).create({
            'name': self.name,
            'model': self.model_name,
            'state': 'manual',
            'field_id': [(0, 0, f) for f in bve_fields._prepare_field_vals()],
        })

        # give access rights
        self._build_access_rules(model)

        # create tree, graph and pivot views
        self._create_bve_view()

    def _check_groups_consistency(self):
        self.ensure_one()

        if not self.group_ids:
            return

        for line_model in self.line_ids.mapped('model_id'):
            res_count = self.env['ir.model.access'].sudo().search([
                ('model_id', '=', line_model.id),
                ('perm_read', '=', True),
                '|',
                ('group_id', '=', False),
                ('group_id', 'in', self.group_ids.ids),
            ], limit=1)
            if not res_count:
                access_records = self.env['ir.model.access'].sudo().search([
                    ('model_id', '=', line_model.id),
                    ('perm_read', '=', True),
                ])
                group_list = ''
                for group in access_records.mapped('group_id'):
                    group_list += ' * %s\n' % (group.full_name, )
                msg_title = _(
                    'The model "%s" cannot be accessed by users with the '
                    'selected groups only.' % (line_model.name, ))
                msg_details = _(
                    'At least one of the following groups must be added:')
                raise UserError(_(
                    '%s\n\n%s\n%s' % (msg_title, msg_details, group_list,)
                ))

    def _check_invalid_lines(self):
        self.ensure_one()
        if not self.line_ids:
            raise ValidationError(_('No data to process.'))

        if any(not line.model_id for line in self.line_ids):
            invalid_lines = self.line_ids.filtered(lambda l: not l.model_id)
            missing_models = set(invalid_lines.mapped('model_name'))
            missing_models = ', '.join(missing_models)
            raise ValidationError(_(
                'Following models are missing: %s.\n'
                'Probably some modules were uninstalled.' % (missing_models,)
            ))
        if any(not line.field_id for line in self.line_ids):
            invalid_lines = self.line_ids.filtered(lambda l: not l.field_id)
            missing_fields = set(invalid_lines.mapped('field_name'))
            missing_fields = ', '.join(missing_fields)
            raise ValidationError(_(
                'Following fields are missing: %s.' % (missing_fields,)
            ))

    def open_view(self):
        self.ensure_one()
        self._check_invalid_lines()
        [action] = self.action_id.read()
        action['display_name'] = _('BI View')
        return action

    @api.multi
    def copy(self, default=None):
        self.ensure_one()
        default = dict(default or {}, name=_("%s (copy)") % self.name)
        return super().copy(default=default)

    def action_reset(self):
        self.ensure_one()

        has_menus = False
        if self.action_id:
            action = 'ir.actions.act_window,%d' % (self.action_id.id,)
            menus = self.env['ir.ui.menu'].search([
                ('action', '=', action)
            ])
            has_menus = True if menus else False
            menus.unlink()

            if self.action_id.view_id:
                self.sudo().action_id.view_id.unlink()
            self.sudo().action_id.unlink()

        self.env['ir.ui.view'].sudo().search(
            [('model', '=', self.model_name)]).unlink()
        models_to_delete = self.env['ir.model'].sudo().search([
            ('model', '=', self.model_name)])
        if models_to_delete:
            models_to_delete.unlink()

        table_name = self.model_name.replace('.', '_')
        tools.drop_view_if_exists(self.env.cr, table_name)

        self.state = 'draft'

        if has_menus:
            return {'type': 'ir.actions.client', 'tag': 'reload'}

    def unlink(self):
        if self.filtered(lambda v: v.state == 'created'):
            raise UserError(
                _('You cannot delete a created view! '
                  'Reset the view to draft first.'))
        return super().unlink()

    @api.model
    def _sync_lines_and_data(self, data):
        line_ids = [(5, 0, 0)]
        fields_info = []
        if data:
            fields_info = json.loads(data)

        table_model_map = {}
        for item in fields_info:
            if item.get('join_node', -1) == -1:
                table_model_map[item['table_alias']] = item['model_id']

        for sequence, field_info in enumerate(fields_info, start=1):
            join_model_id = False
            join_node = field_info.get('join_node', -1)
            if join_node != -1 and table_model_map.get(join_node):
                join_model_id = int(table_model_map[join_node])

            line_ids += [(0, False, {
                'sequence': sequence,
                'model_id': field_info['model_id'],
                'table_alias': field_info['table_alias'],
                'description': field_info['description'],
                'field_id': field_info['id'],
                'ttype': field_info['type'],
                'row': field_info['row'],
                'column': field_info['column'],
                'measure': field_info['measure'],
                'in_list': field_info['list'],
                'relation': field_info.get('relation'),
                'join_node': field_info.get('join_node'),
                'join_model_id': join_model_id,
            })]
        return line_ids

    @api.constrains('line_ids')
    def _constraint_line_ids(self):
        models_with_tables = self.env.registry.models.keys()
        for view in self:
            nodes = view.line_ids.filtered(lambda n: n.join_node)
            nodes_models = nodes.mapped('table_alias')
            nodes_models += nodes.mapped('join_node')
            not_nodes = view.line_ids.filtered(lambda n: not n.join_node)
            not_nodes_models = not_nodes.mapped('table_alias')
            err_msg = _('Inconsistent lines.')
            if set(nodes_models) - set(not_nodes_models):
                raise ValidationError(err_msg)
            if len(set(not_nodes_models) - set(nodes_models)) > 1:
                raise ValidationError(err_msg)
            models = view.line_ids.mapped('model_id')
            if models.filtered(lambda m: m.model not in models_with_tables):
                raise ValidationError(_('Abstract models not supported.'))

    @api.model
    def get_clean_list(self, data_dict):
        serialized_data = json.loads(data_dict)
        table_alias_list = set()
        for item in serialized_data:
            if item.get('join_node', -1) in [-1, False]:
                table_alias_list.add(item['table_alias'])

        for item in serialized_data:
            if item.get('join_node', -1) not in [-1, False]:
                if item['table_alias'] not in table_alias_list:
                    serialized_data.remove(item)
                elif item['join_node'] not in table_alias_list:
                    serialized_data.remove(item)

        return json.dumps(serialized_data)
